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In vitro
inhibition of the paraoxonase from human serum with sulfonamide
Selma Sinan
Balikesir University, Science and Art Faculty, Department of
Biology/Biochemistry Section, 10145 Balikesir, Turkey.
E-mail:
soznur@balikesir.edu.tr.
Tel: +90 0266 6121278. Fax: +90 0266 6121215.
Accepted
1 February, 2008 |
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This study was conducted to determine the in vitro
effects of sulfonamide on human serum paraoxonase (PON1)
activity. The enzyme was purified by two-step using ammonium
sulfate precipitation and
sepharose-4B-L-tyrosine-1-napthylamine hydrophobic
interaction chromatography. Sulfonamide was an effective
inhibitor on purified human serum PON1 activity for
phenylacetate and paraoxon as substrates with IC50
values of 0.22 and 0.81 mM, respectively. The kinetics of
interaction of sulfonamide with the purified enzyme
indicated a different inhibition pattern for two substrates.
Sulfonamide showed a non-competitive inhibition with Ki
of 0.0037 ± 0.0009 mM for phenylacetate and competitive
inhibition with Ki of 0.0057 ± 0.0002 mM for
paraoxon.
Key
words:
Paraoxonase, sulfonamide, inhibition, in vitro. |
